The present invention relates to an improved flaring tool, and, more particularly, to an improved tube or pipe flaring tool the manual operation of which is more convenient than is the operation of prior art flaring tools.
A typical flaring tool comprises a plurality of adjacent, facing and separable die blocks. Adjacent blocks each contain one-half of one or two circular cross-section passageways. Each passageway half ends at a diameter of its cross-section. When adjacent blocks are held together, the now complete passageways define forming dies. Each passageway or forming die may be flared or diametrically enlarged at one end. A conical member is progressively movable into and against a metal tube or pipe held and gripped in the complete passageway in the vicinity of the die flare to flare outwardly the tube between the conical member and the die flare. To aid in holding the tube during flaring, the walls of the complete passageways may contain circumferential or helical grooves.
The diameters of the complete passageways vary to permit the flaring of tubes having varying OD's. Each diameter is slightly less than the OD of its related tube, so that a tube placed between adjacent blocks when they are separated or expanded will be firmly gripped and held when the passageway is completed by moving and holding the blocks together. After the tube is flared, the blocks must be re-separated or re-expanded to permit the tube and its now increased diameter flare to be removed from between the die blocks.
In one type of prior art device, a line of die blocks slide together and apart radially (or diametrically), that is, along a radius (or diameter) of the passageways and the passageway halves. The die blocks are constrained to so slide by a U-shaped member or strap. The strap fits into complementary relieved areas formed in outside opposed die block walls which are parallel to the direction of block movement. Thus, die block movement is transverse to the major axes of the passageways and of the passageway halves. The passageways are completed and the die blocks are clamped together by exerting a clamping force on the terminal die block at one end of the line of blocks to move the die block at the other end of the line against the bridge of the U. The clamping force may be exerted by a clamping member, such the end of as a screw threaded into and retained by a clamp block held between the legs of the U at its open end. Moving the screw end away from the line of blocks, permits the blocks to expand or move apart so as to facilitate placement or removal of a tube into or from a passageway.
In one type of prior art flaring tool, the clamp block is rotatable between the legs of the U. This, in theory, obviated the need to move the screw member away from the line of blocks the distance necessary to permit sufficient expansion of the blocks for tube placement or removal. Specifically, limited movement of the screw end away from the die blocks thereafter permitted rotation of the clamp block and the retained screw to entirely remove the screw from the path of sliding movement of the blocks, thus permitting free expansion of the blocks. In practice, this arrangement requires a user to manually hold the screw or clamp block to maintain the screw in alignment with the path of movement of the die blocks during both clamping and unclamping. Manually maintaining such alignment during unclamping is necessary to permit controlled removal of a now flared tube. Uncontrolled and/or rapid rotation of the clamp block and screw away from the die block movement path permits the blocks to uncontrollably and/or rapidly expand. This may result in the tube falling out of its expanded passageway and onto a floor or work surface, possibly damaging or nicking the flare. Manually maintaining the alignment of the screw with the block movement path during clamping prevents the increasing force between the screw and the terminal block from inadvertently causing the block and the screw to rotate and unclamp the die blocks.